The present invention relates to a nozzle, a device and a method for generating high-speed uniform nanoparticles. Although the present invention can be used for a variety of usages such as removing nano-pollutants, digging a groove of a nano-size, adjusting roughness of a surface and the like, background arts of the present invention will be described hereinafter focusing on a micro particle generation and injection device used in a dry washing device since it is general that the high-speed micro particle generation and injection device is frequently used in a dry washing device targeting Flat Display Panels (FDPs), semiconductor elements or the like.
A washing device or method can be largely classified as a wet washing method or a dry washing method. The dry washing method among the methods means a method of generating sublimation particles and dropping and removing pollutants by injecting the sublimation particles onto the surface of a contaminated object.
In generating the sublimation particles, a method of supplying a gas, a liquid or a mixture of a gas and a liquid to a nozzle, transforming the gas, the liquid or the mixture into solid particles and injecting the particles is generally used.
U.S. Pat. No. 5,062,898 has disclosed a surface washing method using aerosol of an extremely low temperature. Specifically, this is a method of forming argon gas into aerosol by expanding a mixture gas and washing a surface of an object, and it includes a heat exchange process for cooling down the aerosol to a liquefaction point to implement an extremely low temperature of the aerosol.
On the other hand, Korean Laid-opened Patent No. 10-2006-0079561 has disclosed a washing device for generating solid particles using carbon dioxide and argon by providing a separate cooling device and injecting the solid particles using a carrier gas. In addition, Korean Laid-opened Patent No. 10-2004-0101948 has disclosed an injection nozzle including a separate heating device for heating the carrier gas.
On the other hand, performance parameters of the dry washing device are determined by a size of a washing particle, uniformity of the size, a number density, an injection speed and the like.
First, from the aspect of the size of a washing particle, a size of a sublimation particle should be small in proportion to the size of a pollutant to be washed. Sublimation particles of a nano-size are required to remove pollutants of a size smaller than 100 nm.
In addition, from the aspect of washing power, injection speed of the sublimation particles should be high to have a high washing power, and a supersonic speed is required to remove pollutants of 10 nm class.
However, the dry washing device according to the prior art described above has a problem in that the size and speed of a particle is highly limited.
First, when sublimation particles are generated using argon gas, the argon gas should be supplied after being precooled as much as close to a liquefaction temperature of nitrogen by providing a separate cooling device, and thus the speed of injecting the sublimation particles should be reduced. In addition, since it is difficult to control the temperature when the argon gas is precooled, there is a problem in that sublimation particles of high number density and uniformity are difficult to generate.
Contrarily, when the sublimation particles are generated using carbon dioxide, it is advantageous in that the sublimation particles can be generated comparatively easily at a room temperature without separately controlling the temperature. However, although sublimation particles larger than a micro-size can be easily generated using the carbon dioxide, there are a lot of technical difficulties in generating sublimation particles of a nano-size.